This function is provided by the package
LLLBases.
The first n-1 columns of the matrix z form a basis of the kernel of the n integers of the list s, and the dot product of the last column of z and s is the gcd g.
The method used is described in the paper:
Havas, Majewski, Matthews,
Extended GCD and Hermite Normal Form Algorithms via Lattice Basis Reduction, Experimental Mathematics 7:2 p. 125 (1998).
For an example,
i1 : s = apply(5,i->372*(random 1000000))
o1 = {111019680, 265291800, 159065340, 112315728, 211763604}
o1 : List
|
i2 : (g,z) = gcdLLL s
o2 = (372, | 9 -8 -11 -32 -19 |)
| -8 2 -27 3 -1 |
| 0 -15 21 40 7 |
| 10 15 -6 32 15 |
| 0 5 27 -34 -2 |
o2 : Sequence
|
i3 : matrix{s} * z
o3 = | 0 0 0 0 372 |
1 5
o3 : Matrix ZZ <--- ZZ
|